Asimilacijakolesterola i dekonjugacija žučnih soli s probiotičkimsojem Bifidobacteriumanimalis BB-12

undergraduate thesis

• Title (english): Assimilation of cholesterol and bile salts deconjugation by probiotic strain Bifidobacterium animalis BB-12
• Author: Matea Vrdoljak
• Mentor: Jasna Novak (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Antibiotic, Enzyme, Probiotic and Starter Cultures Technology); Zagreb
• Defense date and country: 2014-09-11, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Svojstvo probiotičkih sojeva da dekonjugiraju žučne soli vrlo često doprinosi i njihovoj toleranciji na visoke koncentracije žuči i poboljšanom preživljavanju uvjeta u gastrointestinalnom traktu te učinku snižavanja koncentracije kolesterola u organizmu domaćina. Za određivanje bazičnih i kiselih svojstava površine mikrobnih stanica korištena je metoda mikrobne adhezije na otapala te je soj Bifidobacterium animalis BB-12 pokazao visok postotak adhezije u kloroformu što upućuje na lužnata (elektron-donorska) svojstva površine bakterijskih stanica. Kvantitativno određivanje hidrolazne aktivnosti je provedeno mjerenjem koncentracije kolne kiseline koja nastaje iz konjugiranog natrijevog taurokolata dodanog u MRS podlogu tijekom 24 sata inkubacije B. animalis BB-12, a radi usporedbe također su provedena i ispitivanja s pojedinim sojevima iz roda Lactobacillus. Svi sojevi pokazuju slabu aktivnost hidrolaze žučnih soli jer su dekonjugirali svega 10-15% taurokolata dodanog u hranjivu podlogu. Soj Lactobacillus sp. 4 je uspješno rastao u hranjivoj podlozi i uz dodatak visoke koncentracije žučnih soli, što znači da su neki drugi mehanizmi uključeni u zaštitu stanica od djelovanja žučnih soli. Poznato je da bi F0F1-ATPaza sustav mogao biti odgovoran za povećanu rezistenciju nekih BMK na djelovanje žučnih soli. Probiotičke bakterije također mogu utjecati na apsorpciju kolesterola dekonjugacijom žučnih soli, sprječavajući reapsorpciju kolesterola ili izravnom asimilacijom kolesterola.

Abstract (english)

Bile salt deconjugation by probiotic strains is often closely linked to bile tolerance and survival of the strains in the gut and lowering of cholesterol in the host.For the determination of basic and acidic properties of the surface of microbial cells, the method of microbial adhesion to the solvents and the strain of Bifidobacterium animalis BB-12 showed a high percentage of adhesion in chloroform suggesting on a basic (electron-donor) properties of the surface of bacterial cells. Quantitative determination of the hydrolase activity was conducted by measuring the concentration of cholic acid which is formed from a conjugated sodium taurocholate added to MRS media during 24 hours of B. animalis BB-12 incubation. In addition, for the comparison the same tests were conducted with some probiotic strains from Lactobacillusgenus. All strains showed weak bile salt hydrolase activity since they have deconjugate only 10-15% of taurocolate in the media.Strain of Lactobacillus sp. 4 successfully growed in nutrien medium with addition of a high concentrations of bile salt simplying that other mechanisms are involved in the protection of cells against the effects of bile salts. It is known that the F0F1-ATPase system could be responsible for the increased resistance of some BMK action to bile salts. Probiotic bacteria can also affect the absorption bile salts deconjugation of cholesterol, preventing reabsorption of cholesterol or direct assimilation of cholesterol.

• Keywords: Bifidobacterium animalis BB-12; dekonjugacija žučnih soli; kolesterol
• Keywords (english): Bifidobacterium animalis BB-12; bile salts deconjugation; cholesterol
• Language: croatian
• URN:NBN: urn:nbn:hr:159:256625
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-04-27 10:13:15